1. Technical Field
The present invention relates to a micropump of a peristaltic type that continuously transfers a fluid through depression of an elastic tube, and a tube unit and a control unit configuring the micropump.
2. Related Art
A previously known infusion pump infuses an infusion liquid filled in a liquid container, i.e., reserver, through depression of a tube. Such an infusion pump is configured to include tube depression means, drive means, and control means. The tube depression means continuously presses and closes a part of the tube, i.e., depression position, in such a manner as to make the infusion liquid to flow in accordance with the set quantity of the infusion liquid. The drive means includes a motor for driving the tube depression means, and the control means is for controlling the drive means. As an example, refer to Patent Document 1 (JP-A-7-59853, p. 3, and FIGS. 1 to 3).
With the infusion pump of Patent Document 1, an elastic tube linked to a reserver is attached, through insertion, to a peristaltic pump section of an infusion pump. An infusion liquid is managed in terms of quantity of flow through control over the rotation speed of the drive shaft of a motor. For control over the rotation speed as such, the pulse frequency in accordance with the set quantity of flow is supplied to a motor drive circuit.
The problem with such an infusion pump is that the tube varies in internal diameter, and this causes another variation of the quantity of infusion liquid. The variation of internal diameter is not negligible especially with infusion of a very small quantity.
Another problem with the infusion pump above is that when a user attaches a new tube to the infusion pump, there is no validation means to see whether the tube is made for attachment to the pump, thereby possibly causing wrong attachment of tube. When the liquid is drug preparations for medical treatment use, such wrong attachment is never permissible.
To prevent such a variation of internal diameter of the tube, and to prevent such wrong attachment of the tube, there is a possibility of fixing the combination between an infusion pump and a tube. This, however, requires replacement all at once of both the infusion pump and the tube being in a piece, and thus a problem of increasing the running cost is expected.
Another problem is that attaching the tube to the peristaltic pump section is difficult to be exact at position, and when the pump is smaller in size to allow a user to carry it around or to mount it to any other type of device, replacement and attachment of the tube may become difficult.